The radial artery usually passes on the radial side of the wrist lateral to the wrist to enter the anatomical snuff box and dorsum of the hand. If the radial artery passes anterior to the wrist, it usually enters the carpal tunnel, and in such cases, it may lead to the compression of the median nerve within the carpal tunnel. During the routine dissection, we found a case of the unusual radial arterial branch that passed anterior to the wrist yet outside the carpal tunnel. The artery passed within a tunnel formed by the fibromuscular fibers of thenar muscles arising from the anterior aspect of the transverse carpal ligament. Knowledge of the course and distribution of the variant superficial palmar branch of radial artery are of importance to the surgeons operating around the wrist, radiologist interpreting angiograms, and orthopedists managing trauma to the wrist.
Keywords: Carpal tunnel; Flexor retinaculum; Radial artery; Superficial palmar branch; Thenar muscles.